The present invention relates generally to telecommunications, and more specifically to wireless messaging systems.
In connection with communication systems, especially radiotelephone and paging systems, it is well known that the identity and/or functionality of particular subscriber receiver units with whom a calling party or the communication network operator wishes to establish a communication channel is either predetermined and fixed, or can be selected a priori either by the calling party, the communication network operator, or the particular subscriber themselves. By a priori it is implied that the selection is done prior to reception of data by the particular subscriber receiver units.
FIG. 1 depicts the high level operation of a typical prior art communication network. In the figure, a first device originates a request for establishing communication with any one or several of second communication devices. The first device connected to the communication network either via the internet or via a regular Plain Old Telephone System (POTS). Of course, other connecting technologies may also be used for connecting the first communication device to the communication network. The message from the first communication device is packaged and transmitted by the communication network operator to several second communication devices through localized Towers or Base Stations or Exchanges (nomenclature well recognized by one skilled in the art). Only a subset of the several second communication devices recognizes its address embedded in the transmitted message and consequently only this subset receives the transmitted message.
FIG. 2 depicts the operation of a prior art second communication device used in conjunction with the existing communication network depicted in FIG. 1. The transmitted signal contains an identification tag, labeled Transmitted ID in the figure, indicating which one or several of the second communication devices are to process the accompanying message data. The box labeled Front End in the figure encapsulates all the circuitry in the device required for interfacing the device with the communication network and extracting the contents of the transmitted signal (i.e., Transmitted ID and Message). The Transmitted ID is checked for equivalence with a locally stored ID and if there is a match (i.e., the two are equal), the accompanying Message data is further processed to result in some appropriate action (e.g., display of message, generation of tone, etc.). If there is no match the Message data is discarded and the receiver simply ignores the incoming transmitted signal.
For ease of understanding, the block diagram of the communication device in FIG. 2 is divided into three different spaces: Data Space, Filter Space, and Action Space. The Data Space in FIG. 2 simply consists of one or several pre-defined numerical values (referred to here as ID values) using which the particular device can be identified. These ID values may be unique or shared with other devices; however, in all cases they are predetermined before transmission of data to the device. The Filter Space is responsible for checking equality between Transmitted ID and local ID and generating a True/False answer. In essence the output of the Filter Space determines whether or not the Transmitted Message was intended for reception by the communication device. The Action Space is the result of processing of the received message in the event Filter Space returns True, else it is null, i.e., there is no action.